Place one full graham cracker on a cutting board. Use a serrated knife to carefully cut diagonally across the top half as shown (a gently sawing motion works best).
Cut the other two graham crackers in half so you have four graham cracker halves and two graham cracker halves with triangle shapes on top (they will support the roof).
Lay one roof support cracker in between two graham cracker halves. Pipe a line of melted white chocolate (or royal icing) down each side of the graham cracker halves.